Phased Array Fed Reflector Antenna for OAM-Generating and Beam-Scanning Applications

This paper shows the design concept of a reflector antenna with a small Vivaldi array feed antenna. The proposed design is employed for launching angular momentum (OAM) beams, as well as beam scanning applications. In the design procedure, the working mechanisms of the Vivaldi array fed-reflector are discussed firstly. Then, the design details of the Vivaldi array feed are analyzed, followed by the discussions of multi-mode OAM beams and scanning beam radiation patterns. Thanks to the inherent multi-beam abilities of the reflector, the 0-OAM-mode beam can be steered over a conical scanning range of ±10°. Moreover, the flexible excitations of the Vivaldi array feed provide more possibilities to superpose multiple OAM states simultaneously, which can enhance the spectrum efficiency and the channel capacity.